This meta-analysis sets out to systematically assess the efficacy of short course radiation (SRT) for rectal cancer patients based on randomized, controlled trials. Eight randomized controlled trials involving 6894 patients were ultimately included in this meta-analysis. Three trials (n = 2574) compared SRT with surgery alone. Local recurrence was improved (HR = 0.48, 95% CI 0.40 to 0.58). Overall survival was marginally improved with an HR of 0.90 (95% CI 0.81 to 1.00), but the magnitude of benefit was heterogeneous across trials. An additional three trials (n = 3682) compared SRT with selective postoperative radiation ± chemotherapy. A significant reduction of local recurrence (HR = 0.44, 95% CI 0.35 to 0.56) was also found after SRT. However, no benefit in overall survival was observed. Moreover, two trials (n = 638) compared SRT with long course chemoradiation. There was no statistically significant local recurrence or overall survival difference observed between the two strategies. Patients receiving SRT had lower grade 3 or 4 acute treatment related toxicity (RR 0.11, 95% CI 0.05 to 0.22) whereas no difference in late toxicity was observed. Overall, SRT is a reasonable alternative for resectable rectal cancer patients and should be part of an informed discussion of treatment options for this group of patients.